Posted: 8/31/2006 9:15:53 PM EDT
How does muffler size effect the torque of your engine? I am thinking of getting a Magnaflow muffler to replace the OEM on my Mitusbishi Montero Sport v6 3.0. My concern is moving the torque curve too high in the RPM range where the gains are only effective at 65-70 MPH. I don't want to lose the low end when I'm driving around town and the RPM's don't don't climb above 3k. Ideas? Thanks.
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ee alot of torque from just the muffler but I have no clue... so consider BTT
I'm not much for advertising hype, but Gibson is one of the only ones that state their mufflers are made specifically for low to mid range torque, where most real world driving is done. I see a bunch of articles on their website and it seems a lot of trucks use them. Magnaflow, Dynomax, and Flowmaster all talk about reducing backpressue and maximizing "power". To me, it sounds like these companies are saying your power will increase without telling you that the torque and hp curves will be moved up where they just aren't practical for real world driving.
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a muffler with the same diamiter as the stock intake will do nothing for power in reality.(maybe give you a tenth of an HP) you will only really start to gain power with a cat back system(even then, a cat back still builds up excess back pressure at the cat.) headers, high flow cats(you could run test pipes, but a good ceramic packed high flow cat will flow nearly as well) and independant piping(1 independant pipe per bank of the v6) larger pipes tend to add high end, less back pressure, usually = a better top end, maintaining some back pressure(within reason) = a little more mid to low. if the stock muffler doesnt have a hole, leave it alone, or replace it with a real exhaust... be ready for more volume though. i dont know how much a muffler install runs, i have never gotten one, i either have a friend with a mandrel bender make me a single pipe with muffler back from the cat(1 piece = less chance for leaks over time, you wont find it in a aftermarket replacment as a 1 piece doesnt compensate for chasis flex) or i buy an aftermarket setup and go for the heads back.(i also always install a CAI or ramair setup) dont waste your money if u dont have a hole for just a muffler. |
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My Ram doesn't have a muffler. It did lose a little bit of low-end when I had it taken off but when you get on it hard it actually starts pushing you back into the seat once you hit around 3K RPMs. It would never do that stock or even with the |
| As said above if you replace your mufller with one of the better brands and get the same inlet and outlet size if there was difference you would not notice it. Yes cat back sytems are better but we have dynoed allot of them and some are waaaaay better than others. Sorry to disagree but Gibson was not one of the better ones. Personally I have had all my rigs dualed out from the manifolds to out the back, I have used hiflow cats and equalizer tubes. Its amazing what the equalizer tubes do. But for your situation you will be fine staying with a good brand replacement. I would look into a high flow cat back pressure is good but todays sytems are designed for emissions and to be cheap to manufacture. You will get more than enough back pressure from your manifolds. |
when u say equalizer tubes.... what u mean? i know setups i just dont know the proper names... |
thats what i thought it was but i wasnt sure. thanks. |
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Here are the measurements for my OEM muffler: 2001 Montero Sport 3.0L Length 19" Width 9.5" Circumference 28" Height 6" Pipe Diameter 2" Measurements are +/- 1 or 2 inches to allow for play room. With these measurments, I ended up ordering a Magnaflow, part # 12244. This has a 2" piping. You can go with part # 12245 if you want 2.25". The Magnaflow I ordered is 5x8 oval 2" diameter pipe, 18" body, total 24" including pipe extrustions from front and back of muffler and satin steel. I figured I'd save some money by not going polished. Now to figure out a nice exhaust tip to make a side exit. On the intake end, I added a K&N drop in filter. I just pulled it out of the box pre oiled and dropped it in. I have read about people over oiling the filter and mucking up their MAF. I believe that oily and dirty MAF's are due to over oiling your air filter. Anyway, I also went to Jury Rig Central a.k.a Home Depot to find some PVC piping plugs to plug up the air resonators and create a more "direct" flow. i.e. filling the airbox only and not the resonators. The resonators are used just for noise cancellation anyway. The engine is a BIT louder. I haven't installed the muffler yet. Auto experts, let me know what you think. Reading this over before posting, sounds like junkyard science, but heck, I like tinkering with stuff.  |